METHOD AND APPARATUS FOR DECOUPLING ENVIRONMENTAL AND MODAL DEPENDENCIES IN INERTIAL MEASUREMENT DEVICES

• US 20160327390A1
• Filed: 01/13/2015
• Published: 11/10/2016
• Est. Priority Date: 01/13/2014
• Status: Abandoned Application

• Current Assignee: Panasonic Holdings Corporation
• Original Assignee: Qualtre Incorporated (Panasonic Holdings Corporation)
• Inventors: Serrano, Diego E., Zaman, Mohammad F., Rahafrooz, Amir, Sung, Wang-Kyung, Jafri, Ijaz, Ayazi, Farrokh
• Application Number:
  US15/111,016
• Publication Number:
  US 20160327390A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01C 19/5698 using acoustic waves, e.g. surface acoustic wave gyros
• CPC Class Codes: H03H 3/02 for the manufacture of piezoelectric or electrostrictive resonators or networks H03H3/08 takes precedence
• CPC Class Codes: H03H 9/02007 of bulk acoustic wave devices
• CPC Class Codes: H03H 9/17 having a single resonator crystal tuning forks H03H9/21

Abstract

A resonant gyroscope apparatus has a decoupling mechanism implemented with spring-like flexure members to effectively isolate an axis-symmetric bulk-acoustic wave (BAW) vibratory gyroscope from its substrate, thereby minimizing the effect that external sources of error have on offset and scale-factor. The spring-like structure enables degeneracy of in-plane resonance modes of the annulus and aids in decoupling the in-plane and out-of-plane resonance modes of the resonant annulus, thereby enabling the mode-matched and/or near mode-matched operation of the structure as a vibratory gyroscope in the pitch, roll and yaw-modes. In various embodiments, the decoupling mechanism may be coupled to either an interior or exterior perimeter of an annulus shaped resonator element of the gyroscope

Claims

1. The resonant apparatus comprising:

a resonant member;

a structure for supporting the resonant member relative to a another surface, and

a decoupling mechanism for flexibly decoupling the resonant member from the support structure.

2. The apparatus of claim 1 wherein the resonant member has is substantially annulus shaped.

3. The apparatus of claim 1 wherein the structure for supporting the resonant member comprises an anchor.

4. The apparatus of claim 3 wherein the anchor is coupled to a substrate.

5. The apparatus of claim 1 wherein the decoupling mechanism comprises a plurality of springs coupling a perimeter the resonant member to the supporting structure.

6. The apparatus of claim 5 wherein the plurality of springs are arranged in mirrored pairs about the perimeter the resonant member.

7. The apparatus of claim 5 wherein each of the springs comprises a flexure member having a first end coupled to the perimeter of the resonant member and a second end coupled the supporting structure.

8. The apparatus of claim 7 wherein the flexure member has at least one substantially right angle transition between the first end and the second end in an unflexed mode.

9. The apparatus of claim 7 wherein the flexure member has at least four substantially right angle transitions between the first end and the second end when in an unflexed mode.

10. The apparatus of claim 7 wherein the flexure member has at least eight substantially right angle transitions between the first end and the second end when in an unflexed mode.

11. The apparatus of claim 7 wherein the flexure member has at least twelve substantially right angle transitions between the first end and the second end when in an unflexed mode.

12. The apparatus of claim 1 wherein the decoupling mechanism enables degeneracy of in-plane resonance modes of the resonant member.

13. A gyroscope apparatus comprising:

a substantially annulus shaped resonator element having a pattern of flexure members extending outward therefrom; and

a structure for supporting the resonant member relative to a another surface, and

wherein each flexure member has a plurality of substantially right angle transitions between first and second ends thereof.

14. A method of manufacturing a bulk acoustic wave resonator element comprising:

A) forming an annulus shaped resonator element having a perimeter edge;

B) etching a plurality of apertures in the resonator element to collectively define a plurality of springs extending from the perimeter edge, wherein the springs each of the springs comprises a flexure member having a plurality of substantially right angle transitions.

15. An article of manufacture comprising an annulus shaped resonator element separated from a support structure by a plurality of springs connecting, wherein each of the springs comprises a flexure member having a plurality of substantially right angle transitions between junctures with the annulus shaped resonator element and support structure.

16. The article of manufacture of claim 15 wherein each of the support structure comprises a plurality of support structures disposed about an exterior perimeter of the annulus shaped resonator element.

17. The article of manufacture of claim 15 wherein support structure comprises an annulus shaped support structures disposed about an exterior perimeter of the annulus shaped resonator element.

18. The article of manufacture of claim 15 wherein support structure comprises a central anchor disposed within an interior perimeter of the annulus shaped resonator element, so that the resonator element is axis symmetric about the support structure.

19. The article of manufacture of claim 15 wherein the plurality of springs are arranged in mirrored pairs.